在硫酸盐镀锌液中所得的含铅与不含铅的镀锌试片 ,经铬酸盐钝化后 ,通过湿热试验 (HCT)进行了黑变培养。采用试片的表面明度差来表征黑变的程度 ,考察了铅和光照对其黑变速率的影响。发现镀液中铅离子的存在使黑变反应的活化能Ea 从 34kJ/mol左右降低到 2 1kJ/mol左右 ,从而加速了黑变反应。光照虽然使Ea 降低了 0 .5kJ/mol,但同时较大幅度地降低了指前因子A的值 ,总的作用结果是抑制了黑变的反应 The lead-free and lead-free galvanized coupons obtained in the sulphate zinc plating solution were chromate-conditioned after chromate passivation by a hydrothermal test (HCT). The degree of blackening was characterized by the surface brightness difference of the test piece, and the influence of lead and light on the blackening rate was investigated. It was found that the presence of lead ions in the bath reduced the activation energy Ea of the blackening reaction from about 34 kJ / mol to about 21 kJ / mol, accelerating the blackening reaction. Although the illumination reduces the Ea by 0.5 kJ / mol, the value of the pre-exponential factor A is greatly reduced at the same time, and the total effect is that the blackening reaction is suppressed